Tire building drum with turn-up apparatus

ABSTRACT

Tire building drum with turn-up apparatus for building an unvulcanized tire with tire components ( 1, 2 ) and two bead cores ( 3, 4 ) with high bead filling strips ( 4 ′). Said drum has two ring segments ( 6, 7 ) spaced from each other in order to support a bead core, drum segments ( 8, 9, 10, 11, 12 ) placed on the outside of each ring segment in order to support the tire components. Said drum further has means to radially expand that part of the tire components which is situated between the ring segments. Said tire building drum has on both sides outside the ring segments a first and second set of axially extending, hingeable arms ( 11, 12, 17, 19 ) each having an end directed to the ring segment, said end having a roller ( 13, 14, 16, 18 ) and means to axially and radially move each set of arms from a first position in which the rollers of a set of arms form a virtually closed ring to a second position in order to press the expanded part of the tire components which is situated between the ring segments to the part of the tire components which is situated outside the ring segments. Each roller ( 16, 18 ) of an arm ( 17, 19 ) of the second set is situated between two adjacent arms ( 13, 14 ) of said first set and situated on the side of the rollers of the arms of said first set which side is turned away from the ring segments.

BACKGROUND OF THE INVENTION

The present invention relates to a tire building drum with turn-upapparatus for building an unvulcanized tire with tire components ofrubber or having reinforcement cords and two bead cores with high beadfilling strips, said tire building drum having a central axis, two ringsegments placed around the axis and spaced from each other each tosupport a bead core, drum segments placed around the axis and on theoutside of each of the ring segments, which drum segments define acylindrical surface to support tire components, means to radially expandthat part of the tire components which is situated between the ringsegments, the tire building drum having on both sides outside the ringsegments a first set of axially extending, hingeable arms, each armhaving an end directed at the ring segment, said end having a roller,means to axially and radially move each first set of arms from a firstposition in which the rollers of a first set of arms form a virtuallyclosed ring to a second position in order to press the expanded part ofthe tire components which is situated between the ring segments to thepart of the tire components which is situated outside the ring segments.

Such a tire building drum with turn-up apparatus is already known fromBritish patent specification 1.532.960. This known tire building drumcomprises two sets of arms, one set on one side outside of the ringsegments and the other set on the other side outside of the ringsegments. When moving the arms from the first position to the secondposition, rollers are brought at a greater distance from the axis, as aresult of which the rollers are distanced from each other and thus donot form a virtually closed ring any more. Because the second positionis a little distance further from the central axis of the tire buildingdrum than the first position, the part of the tire components situatedoutside the ring segments is not fully pressed over the total height tothe part of the tire components situated between the ring segments, andfurthermore the ends of the arms come to stand at a distance from eachother so that an incomplete circumferential pressure by the rollers isobtained. In order to prevent an incomplete attachment of the tirecomponents, which may be detrimental to the quality of the tire to beproduced, a sleeve of rubber is applied around the arms. Such a sleeveof rubber however, has a limited life span.

SUMMARY OF THE INVENTION

The object of present invention is to provide a tire building drum withturn-up apparatus for building an unvulcanized tire with tire componentsof rubber or having reinforcement cords and two bead cores with highbead filling strips, wherein without the use of a rubber sleeve theparts of the tire components can be pressed to one another over theirfull circumference and their full height, so that the final quality ofthe tire to be produced is improved.

For this purpose a tire building drum with turn-up apparatus of the kinddescribed above is according to the invention characterized in that eachfirst set of arms contains a second set of axially extending, hingeablearms, each arm having an end directed at the ring segment, said endhaving a roller, each roller of an arm of the second set being situatedbetween two adjacent arms of said first set and being situated on theside of the rollers of the arms of said first set which side is turnedaway from the ring segments, and that means are provided to axially andradially move each second set of arms from a first position, in whichthe rollers of a second set of arms form a virtually closed ring to asecond position in order to press the expanded part of the tirecomponents which is situated between the ring segments to the part ofthe tire components which is situated outside the ring segments. Becausethe rollers of the arms of the second set are situated between the armsof the first set, at least almost the entire circumference of the tirecomponent parts is pressed to one another in the second position of therollers of both sets, as a result of which an at least almost completeattachment of the tire components is obtained.

A preferred embodiment of a tire building drum with turn-up apparatusaccording to present invention is characterized in that the means toaxially and radially move each first set of arms and the means toaxially and radially move each second set of arms are formed by the samemeans. In this way the turn-up apparatus of the tire building drumcannot only be manufactured in a more compact design, but also movingthe sets of arms from the first position to the second position issynchronized in a simple way.

A further preferred embodiment of a tire building drum with turn-upapparatus according to the invention is characterized in that means areprovided for laterally supporting the two bead cores with high beadfilling strips, wherein the means are situated between the ring segmentsand preferably are pivotable from a non-working position to a workingposition. In this way it is prevented that when the arms are going fromthe first position to the second position, the arms push the bead coreswith high bead filling strips from their places. When the means arepivotable from a non-working position to a working position, the normalworking of the tire building drum is not detrimentally influenced.

BRIEF DESCRIPTION OF THE DRAWINGS

By way of example, some embodiments of a tire building drum with turn-upapparatus according to the invention will be described on the basis ofthe drawing. Therein:

FIG. 1 schematically shows a longitudinal cross section of an tirebuilding drum with turn-up apparatus according to the invention, thearms being in the first position,

FIG. 2 schematically shows a longitudinal cross section of an tirebuilding drum wi th turn-up apparatus according to the invention, thearms being in the second position and the part of the tire componentswhich is situated between the ring segments, being expanded,

FIG. 3 schematically shows a longitudinal cross section of analternative embodiment of the tire building drum with turn-up apparatusaccording to the invention, wherein in the left half of the figure thearms are shown in the first position and in the right half of the figurethe arms are shown in the second position,

FIG. 4 schematically shows in perspective one set of arms in a firstposition and some parts of the turn-up apparatus of the tire buildingdrum according to the invention in order to exemplify thethree-dimensional configuration, and

FIG. 5 schematically shows in perspective one set of arms in a secondposition and some parts of the turn-up apparatus of the tire buildingdrum according to the invention in order to exemplify thethree-dimensional configuration.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically shows a longitudinal cross section of the tirebuilding drum with turn-up apparatus according to the invention forbuilding an unvulcanized tire. Such an unvulcanized tire contains tirecomponents of rubber or having reinforcement cords (of which in FIG. 1two, 1 and 2 are shown) and two bead cores 3 and 4 with high beadfilling strips. The number and kind of tire components are dependent onthe final tire to be produced, and the possible assemblies andconstruction are sufficiently known to an expert, so a more detaileddiscussion of this will be omitted.

The tire building drum has a central axis 5. Around the the axis 5 andspaced from each other two ring segments 6 and 7 are situated, each tosupport a corresponding bead core 3 respectively 4. Around the axis 5and on the outside of each ring segment 6, 7 drum segments formed byarms 11 and 12 are situated, which drum segments define a cylindricalsurface to support the tire components 1, 2. The ring segments 6, 7 canalso serve to support certain tire components, such as relatively narrowreinforcement strips.

FIG. 1 shows an example of a tire building drum, in this case also withdrum segments 8, 9 and 10 between the ring segments. As already knownthere are means (not represented in the figure) to radially move atleast a part of the drum segments (particularly drum segment 8), andmeans (not represented in the figure) to—for instance by way or airpressure—radially expand that part of the tire components which issituated between the ring segments 3, 4.

The tire building drum on both sides outside the ring segments 6, 7 hasa first se: of axially extending, hingeable arms 11 respectively 12.Each arm 11, 12 has an end directed at the ring segment 6, respectively7, said end having a roller 13, respectively 14. As already known thereare means (15, FIG. 2) to axially and radially move each first set ofarms 11, 12 from a first position (represented in FIG. 1) in which therollers 13, 14 of a first set of arms 11, 12 form a virtually closedring to a second position (represented in FIG. 2) to press the expandedpart of the tire components which is situated between the ring segments6, 7 to the part of the tire components which is situated outside thering segments 6, 7.

In the following the feature of the tire building drum which isessential for the invention will be further gone into, which is theturn-up apparatus, and other components of the tire building drum, whichare sufficiently known to the expert, will not be described in detail.

According to the invention a tire building drum with turn-up apparatusis provided in which each first set of arms (11 or 12) contains a secondset of axially extending hingeable arms (17 respectively 19, see FIGS. 2and 4). Each arm 17, 19 of each second set has an end directed at thering segment 6 respectively 7, said end having a roller 16 respectively18. Each roller 16, 18 of an arm 17, 19 of each second set is situatedbetween two adjacent arms 11, 12 of the said first set, each roller 16,18 of the second set being situated on the side of the rollers 13, 14 ofthe arms 11, 12 of said first set, which side is turned away from thering segments 6, 7.

Furthermore there are means, preferably the means 15, to axially andradially move each second set of arms from a first position in which therollers 16, 18 of the second set of arms 17, 19 form a virtually closedring to a second position in order to press the expanded part of thetire components which is situated between the ring segments 6, 7 to thepart of the tire components which is situated outside the ring segments6, 7. The means to axially and radially move the set of arms preferablycomprise flexible bands, arranged around the set of arms in order topress the arms from the second position back to the first position.

Because the rollers 16, 18 of the arms 17, 19 of the second set aresituated between the rollers 13, 14 of the arms 11, 12 of the first set,in the second position of the rollers of both sets almost the entirecircumference of the tire component parts is pressed to one another (asrepresented in FIGS. 2 and 5) as a result of which an almost completeattachment of the tire components is obtained.

FIG. 3 schematically shows a longitudinal cross section (only the upperhalf is shown, the lower half is symmetric) of an alternative knownembodiment of the tire building drum with turn-up apparatus according tothe invention for building an unvulcanized tire. Such an unvulcanizedtire consists of tire components of rubber or having reinforcementcords, of which in the right half of FIG. 3, two, 1′ and 2′, are shown,and two bead cores with high bead filling strips, of which only one 4′is shown. The tire building drum has a central axis 5′. Around the axis5′ and spaced from each other two ring segments 6′ and 7′ are situated,each to support a corresponding bead core. Ring segments 6′ and 7′ serveto support the tire components 1′ and 2′. Initially two sets of arms11′, 17′ and 12′, 19′ when they are in the first position are used forsupporting the part of the tire components that is outside the ringsegments. Each arm 11′, 12′ (17′, 19′) has an end directed at the ringsegment 6′, respectively 7′, said end having a roller 13′, respectively14′ (16′, 18′). Each set of arms can be moved from a first position(shown in the left half of FIG. 3) in which the rollers of a set of armsform a virtually closed ring to a second position (shown in the righthalf of FIG. 3) in order to press the expanded part of the tirecomponents that is between the ring segments 6′, 7′ to the part of thetire components which is outside the ring segments 6′, 7′.

Each roller 16′, 18′ of an arm 17′, 19′ of each second set is situatedbetween two adjacent arms 11′, 12′ of said first set, each roller 16′,18′ of the second set being situated on the side of the rollers 13′, 14′of the arms 11′, 12′ of said first set, which side is turned away fromthe ring segments 6′, 7′.

Because the rollers 16′, 18′ of the arms 17′, 19′ of the second set aresituated between the rollers 13′, 14′ of the arms 11′, 12′ of the firstset, in the second position of the rollers of both sets, almost theentire circumference of the tire component parts are pressed to oneanother, wherein also without the use a sleeve of rubber an almostcomplete attachment of tire component parts is obtained.

Furthermore means 20, 21 (FIG. 3) are provided to laterally support saidtwo bead cores with high bead filling strips of which one 4′ is shown inFIG. 3, in which the means are situated between the ring segments 6′,7′. Said means, when in working position, prevent that the arms whengoing from a first position to a second position, from unwontedlypushing the bead cores with high bead filling strips from the ringsegments. Preferably the means 20, 21 for laterally supporting the beadcores with high bead filling strips are pivotable from a non-workingposition to a working position. In this way the means for laterallysupporting the bead cores with high bead filling strips do not impedethe normal working of the tire building drum, and moreover can helpsupporting the tire components in the starting position.

What is claimed is:
 1. Tyre building drum with turn-up apparatus forbuilding an unvulcanized tire with tire components of rubber or havingreinforcement cords (1, 2; 1′,2′) and two bead cores (3, 4; 3′, 4′) withhigh bead filling strips, said tire building drum having a central axis(5; 5′), two ring segments (6, 7; 6′, 7′) placed around the axis (5; 5′)and spaced from, each other each to support a bead core (3, 4; 3′, 4′),drum segments formed by arms (11, 12; 11′, 12′) placed around the axes(5; 5′) and on the outside of each of the ring segments (6, 7; 6′, 7′),which drum segments (11, 12; 11′, 12′) define a cylirdrical surface tosupport tire components, means to radially expand that part of the tirecomponents which is situated between the ring segments, the tirebuilding drum having on both sides outside the ring segments (6, 7; 6′,7′) a first set of axially extending, hingeable arms (11, 12; 11′, 12′),each arm (11, 12; 11′, 12′) having an end directed at the ring segment(6, 7; 6′, 7′), said end having a roller (13, 14; 13′, 14′), means (15;15′) to axially and radially move each first set of arms (11, 12; 11′,12′) from a first position in which the rollers (13, 14; 13′, 14′) of afirst set of arms (11, 12; 11′, 12′) form a virtually closed ring to asecond position in order to press the expanded part of the tirecomponents which is situated between the ring segments (6, 7; 6′, 7′) tothe part of the tire components which is situated outside the ringsegments (6, 7; 6′, 7′), characterized in that, each first set of arms(11, 12; 11′, 12′) contains a second set of axially extending, hingeablearms (17, 19; 17′, 19′), each arm (17, 19; 17′, 19′) having an enddirected at the ring segment (6, 7; 6′, 7′), said end having a roller(16, 18; 16′, 18′), each roller (16, 18; 16′, 18′) of an arm (17, 19;17′, 19′) of the second set being situated between two adjacent arms(11, 12; 11′, 12′) of said first set and being situated on the side ofthe rollers (13, 14; 13′, 14′) of the arms (11, 12; 11′, 12′) of saidfirst set, which side is turned away from the ring segments (16, 17;16′, 17′), and that means (15; 15′) are provided to axially and radiallymove each second set of arms (17, 19; 17′, 19′) from a first position inwhich the rollers (16, 18; 16′, 18′) of a second set of arms (17, 19;17′, 19′) form a virtually closed ring, to a second position in order topress the expanded part of the tire components which is situated betweenthe ring segments (6, 7; 6′, 7′) to the part of the tire componentswhich is situated outside the ring segments (6, 7; 6′, 7′).
 2. Tyrebuilding drum with turn-up apparatus according to claim 1, characterizedin that, the means (15; 15′) to axially and radially move each first setof arms (11, 12; 11′, 12′) and the means (15; 15′) to axially andradially move each second set of arms (17, 9; 17′, 19′) are formed bythe same means (15; 15′).
 3. Tyre building drum with turn-up apparatusaccording to claims 1 or 2, characterized in that, means (20, 21) areprovided to laterally support the two bead cores (3, 4; 3′, 4′) withhigh bead filling strips, wherein the means are situated between thering segments (6, 7; 6′, 7′).
 4. Tyre building drum with turn-upapparatus according to claim 3, characterized in that the means (20, 21)to laterally support the bead cores (3, 4; 3′, 4′) with high beadfilling strips are pivotable from a non-working position to a workingposition.
 5. A tire building drum, the drum having a central axis andbeing configured for turning up a turn-up portion of a tire componentabout a bead core, comprising: a first support member, the supportmember disposed radially about the central axis and configured tooperably support a portion of the tire component and the bead core; andfirst and second sets of arms disposed about the central axis, the armsof the second set being interspersed among the arms of the first set,the arms of the first and second sets each having a first end operablyassociated with the first support member and a second end spaced apartfrom the first support member along the central axis and pivotablyassociated with the tire building drum, the arms of the first and secondsets each being movable from a resting position to a working position,wherein, in the working position, the first ends of the arms of thefirst set are disposed at a first radial distance from the central axisand, in the working position, the first ends of the arms of the secondset are disposed at a second, smaller radial distance from the centralaxis, and wherein, upon moving from the resting position to the workingposition, the first and second sets of arms cooperate to press againstsubstantially the full circumference of the turn-up portion of the tirecomponent.
 6. The tire building drum of claim 5, further comprising: asecond support member disposed radially about the central axis andconfigured to operably support a second portion of the tire componentand a second bead core; and third and fourth sets of arms disposed aboutthe central axis, the arms of the fourth set being interspersed amongthe arms of the third set, the arms of the third and fourth sets eachhaving a first end operably associated with the second support memberand a second end spaced apart from the second support member along thecentral axis and pivotably associated with the tire building drum, thearms of the third and fourth sets each being movable from a restingposition to a working position, wherein, in the working position, thefirst ends of the arms of the third set are disposed at a first radialdistance from the central axis and, in the working position, the firstends of the arms of the fourth set are disposed at a second, smallerradial distance from the central axis, and wherein, upon moving from theresting position to the working position, the third and fourth sets ofarms cooperate to press against substantially the full circumference ofa portion of the tire component turned up about the second bead core. 7.The tire building drum of claim 6, further comprising expansion means toradially expand a portion of the tire component disposed between thefirst and second support members.
 8. The tire building drum of claim 5,wherein, in the resting position, the first ends of the arms of thesecond set are disposed at a different distance from the firstsupporting member than the first ends of the arms of the first set toallow the arms of the second set to move from the resting position tothe working position without interfering with the second set of arms. 9.The tire building drum of claim 5, wherein consecutive arms of thesecond set are disposed about an arm of the first set.
 10. The tirebuilding drum of claim 5, wherein the first end of each arm of the firstand second sets comprises a roller.
 11. The tire building drum of claim5, wherein the tire component comprises at least one of unvulcanizedrubber, reinforcing cords, or a high bead filling strip.
 12. The tirebuilding drum of claim 5, wherein the turn-up portion has a height and,in the working position, the arms of the first and second sets cooperateto press against substantially the full height.
 13. The tire buildingdrum of claim 5, wherein the first support member comprises a radialdepression configured to receive a portion of the tire.
 14. The tirebuilding drum of claim 5, wherein the first and second sets of arms areconfigured to move in unison from the first to the second position.